Motor Undervoltage Protection
Motor Undervoltage Protection
(OP)
In a transient stability study I noticed that induction motors are modeled with undervoltage protection. The model shows a voltage pick-up setting of 0.60 pu and a time delay of 30 cycles. Do these values seem right? What is the range of typical settings? Any info would be greatly appreciated.
Michael Sidiropoulos






RE: Motor Undervoltage Protection
The next question is what does the damage curve of the motor look like and what is the maximum time that the motor can stand to get the load rolling. With this information and some homework you should be able to calculate the settings of the protective relay.
RE: Motor Undervoltage Protection
Michael Sidiropoulos
RE: Motor Undervoltage Protection
RE: Motor Undervoltage Protection
IEEE Std 399-1990 {obsolete} Chapter 9 Table 16 suggests a qualified 80% “at terminals of starting motor,” with 71% “at terminals of other motors that must reaccelerate.”
The chapter may have applicable general material for this subject. Current version of the “Brown Book” is IEEE Std 399-1997 Recommended Practice for Industrial and Commercial Power Systems Analysis